I've already preordered, but....
I am going to hold off on the DLC's for now. I want to know for sure that Trion is going to listen to the player base and improve things accordingly before I give them anymore money. In particular, I'm talking about the chat system (or lack of), and possibly some of the other things I see people complaining about. Sure the DLC's probably only cover about a third of what a subscription would, but it's still a huge amount of money if almost everyone buys it. I'm sure Trion knows this, and knowing that they are planning for at least four seasons of the game and show, I think they will be smart about it. Don't let us down Trion!
I played beta #3, and I really liked the gameplay. Despite what other people have said, I think the story is good. You have to remember that it's being developed at the same time as the show, and a good, long-lasting show doesn't answer all the questions in the first episode. An element of mystery keeps people interested in watching/playing and makes for a great experience. I finally saw an advertisement for the show/game before a Hulu movie last night and I was literally cheering. Also, I saw the 14 minute preview of episode 1 and it looks AWESOME! I was very pleased that the soundtrack is shared, as it strengthens the connection between game and show. I have high hopes for the show and the game, and I think both will gain popularity after launch. I'm promoting it to everyone I know, and I hope you will do the same.